Resuscitator for the newly born



July 11,1967 H. H. SAMSON RESUSCITATOR FOR THE NEWLY BORN Filed 001;. 28, 1963 195mm /z 52/1450 3 y MM United States Patent 3,330,272 RESUSCITATOR FOR THE NEWLY BORN Heyrnan H. Samson, 1110 Medical Centre, Jeppee St., Johannesburg, Transvaal, Republic of South Africa Filed Oct. 28, 1963, Ser. No. 319,109 Claims priority, application Republic of South Africa, Nov. 5, 1962, 62/4,657 Claims. (Cl. 128-145.7)

This invention relates to the art of endotracheal and naso-pharyngeal ventilation of newly-born infants.

A doctor or a midwife, confronted with what is popularly known as a blue baby or a white baby, has at present crude methods and potentially dangerous equipment to deal with the emergency. The age-old expedient of slapping the child to induce respiration is of limited efficacy, and in the case of a white baby, which is already in a state of suspended animation due to shock, the slap is likely to hasten its demise. Inflation of the lungs by a tube inserted into the trachea through which positive pressures are imposed on the lungs either by the operators own respiratory system or by a syringe or the like is apt to be a rather hazardous and chancy procedure, since overpressurization is likely to cause damage to the infant.

The object of the present invention is to provide an instrument which is more effective as a resuscitator for newly-born infants than known devices, and is incapable of dangerous overpressurization.

According to the invention, the instrument consists basically in a body, means to attach to the body a resilient bulb and a ventilating device; a passage in the body connecting the bulb cavity to the ventilating device, a port from the passage to atmosphere, a one-way valve controlling flow through the port and closed by pressure within the passage, and a pressure-relief orifice connecting the passage to atmosphere.

An embodiment of the invention is shown in the accompanying drawings in which:

FIGURE 1 is a vertical section through the resuscitator;

FIGURE 2 is a vertical section on the line lIIl of FIGURE 1;

FIGURE 3 is a side view, partly in section, of an endotracheal tube and adapter for attachment to the resuscitator;

FIGURE 4 is a sectional view through a mask that can be used to replace the endotracheal tube of FIG- URE 3.

In the drawings, the apparatus comprises a cylindrical body 16 having an axial passage 12 with counterbores at each end. The counterbore 14 is adapted to receive the spigot 16 of an adapter 18 which includes a stainless steel strainer 17. A plug 19 has a shank 21 that is detachably engaged in a socket 23 in the adapter 18 and which has a spigot 25 that receives an endotracheal tube 20 (FIG- URE 3) or the shank 22 of a mask 24 (FIGURE 4).

The other counterbore 26 of the body receives a tubular plug 28 that incorporates a one-way valve consisting in a disc 30 entrapped in a cage 32 and which cooperates with a seating 34 to prevent flow from the passage 12 to the bore 36 of the plug 28 but to permit it freely in the opposite direction. The plug has a cross-bore 38 that receives one end of a spud 42 the serrated shank 44 of which is intended to be inserted into a pipe that conveys oxygen from a cylinder.

The body is crossbored at 46 to receive one shank 48 of a connector 50. A second shank 52 enters the neck 54 of a rubber bulb 56.

A duct 58 in the connector puts the cavity 60 of the bulb into communication with the passage 12.

Finally, a second plug 62 enters a radial bore 64 on the body and a pressure-relief orifice 66 through it puts the passage 12 into communication with atmosphere. To prevent accidental blocking of the orifice 66 several cross passages 68 are provided between the orifice and atmosphere. The cross-sectional area of the orifice 66 is small compared with the area of the passage 36 in the plug 28.

In use, the ventilating device is selected and attached to the body. It may be the endotracheal tube 20, for insertion into the childs respiratory system or nasopharyngeal tube; or it may be the mask 24 which is placed over his mouth. Compression of the bulb 56 pressurizes the passage 12, closes the valve 39 and forces air into the childs lungs. Any air that cannot be accommodated by the lungs is expelled through the pressure-relief orifice 66. The multiplicity of passages 68 ensures that the orifice 66 cannot be accidentally sealed off by a misplaced finger, to the danger of the infant.

On release, the bulb 56 acts to withdraw into its cavity spent air from the lungs by suction and by the natural recoil of the thoracic cage; and simultaneously draws into the bulb, through the now open valve 30 (and to an insignificant extent through the pressure-relief orifice 66) fresh air from the atmosphere. A fresh compression of the bulb propels gas within the bulb into the lungs, with the surplus again passed to atmosphere through the relief orifice 66; and so on.

Although the major entry of gas into the expanding bulb 56 is from the lungs, harmful carbon dioxide accumulation is prevented by the effective ventilation produced, i.e. by pumping slightly more gas than the physiological tidal volume of the infant. The tidal volume is the correct amount of gas breathed in and out by the infant to maintain the normal oxygenation and carbon dioxide content of the blood. This is done to overcome the inevitable buildup of carbon dioxide returning from the respiratory passages to the bulb. Once resuscitation has been successfully effected and in the event of ventilation having to be manually continued, the rate and degree of compression of the bulb are suitably adjusted to correspond to the normal ventilatory requirements of the infant. At the same time no damage can be done to the lungs, because they will accept only the gas they can accommodate, the rest going to waste. Thus the elasticity of the lungs and of the thoracic cage automatically governs the ratio of gas inhaled to surplus gas exhausted.

The size of the bulb 56, and its relation to the crosssectional area of the passage 12 and the relief orifice 66 are significant and are so selected as to ensure that the lungs are not subjected to harmful forces due to gas pressure. To this end, in the preferred form, the bulb 56 is of the order of cc. in capacity and capable of producing a negative pressure of about 65 mms. of mercury. The cross-sectional area of the passage 12 and of the orifice 66 are such that the maximum possible periodicity permitted the bulb (that is the maximum number of times the bulb can be compressed and allowed to return) is about 60 a minute. This produces ventilation at about the rate of 3 litres a minute, since about 25 cc. are expelled through the escape valve each time the bulb is compressed.

When an oxygen cylinder is connected to the spud 42, the air ingoing to the passage 12 through the valve 30 is enriched with oxygen flowing from the cylinder. Oxygen of some 2 to 3 litres a minute will not disturb the pressure equilibrium of the apparatus and this will raise the oxygen content of the inspired gases to about 60%. Excess pressure in the oxygen source will not be harmful, as the oxygen cylinder is in communication with the atmosphere, as well as with the patient, so that no harm can be done.

Benefits which flow from the use of the resuscitator of the invention are:

(1) The unexpanded lungs can be safely and completely insuifiated with ease and if spontaneous respiration does not start promptly ventilation can be maintained for long periods without difliculty.

(2) The simplicity of the device and its operation make it suitable for use not only by the expert practitioner and nursing staff, but by midwives as well. Since the maximum pressure and volume of the ventilating air are constant at about the optimum required for the average case when the cycle of operation of the bulb is as quick as can be achieved, the apparatus cannot be used unsafely. The smaller the infant, the more gases are forced through the escape orifice 66.

V the heart is facilitated, which is an aid to a shocked infant. A

(5) The apparatus is light, easy to handle and, if made of an acrylic resin, it can be sterilized by boiling.

The mask 24 has thus far been mentioned rather cursorily as a possible alternative to the tube 20. It must be pointed out, however, that it has a specialized feature that makes it suitable for use over a wide range of sizes. This feature is the rim 70 of foamed resilient material such as plastic or rubber, and preferably the former. This material provides a good seal around the mouth and over the nose, which is received in the recess 72; and is sufliciently cheap or the mask to be expendable after a single necting the bulb cavity to the ventilating device, a port from the passage to atmosphere, a one-way valve controlling flow through the port and closed by gas pressure within the passage, a plug detachably secured to the body, a bore within the plug that is in communication with the passage to provide a constantly open pressure-relief orifice, and several cross-bores between the 'bore and the atmosphere.

2. The resuscitator of claim 1 including an extension of the passage upstream of the valve and open to atmosphere, and a means to put a source of oxygen gas into communication with the extension of the passage.

3. The resuscitator of claim 2 in which the extension of the passage is provided within a plug detachably secured to the body and which carries the one-way valve.

'4. A. resuscitator for endotracheal and/ or nasopharyngeal ventilation, consisting in a body, a hollow resilient squeeze bulb of about'75 cc. in capacity and a natural periodicity, when attached to the body, of about per minute, a ventilating device, means to attach the bulb to the body, means to attach the ventilating device, to'the body, a constantly open passage in the body connecting the bulb cavity to the ventilating device, a port from the passage to atmosphere, a one-way valve controlling flow through the port and closed by gas pressure within' the passage; and a constantly open pressure-relief orifice connecting the passage to atmosphere.

5. The resuscitator of'claim 4 including a plug detachably secured to the body, the pressure-relief orifice being provided within the plug.

References Cited UNITED STATES PATENTS 2,774,346 12/1956 11611115111166 12s 29 2,908,270 10/1959 Stanton 128-29 2,931,355 4/19 0 Miller et al. 12s 142 3,046,978 7/1962 Lea 12s -29 ,FoREIGN PATENTS 1,256,024 2/1961 France.

910,065 11/1962 Great Britain.

RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner.

C. F. ROSENBAUM, Assistant Examiner. 

1. A RESUSCITATOR FOR ENDOTRACHEAL AND/OR NASO-PHARYNGEAL VENTILATION CONSISTING OF A BODY, A HOLLOW RESILIENT SQUEEZE BULB, A VENTILATING DEVICE, MEANS TO ATTACH THE BULB TO THE BODY, MEANS TO ATTACH THE VENTILATING DEVICE TO THE BODY, A CONSTANTLY OPEN PASSAGE IN THE BODY CONNECTING THE BULB CAVITY TO THE VENTILATING DEVICE, A PORT FROM THE PASSAGE TO ATMOSPHERE, A ONE-WAY VALVE CONTROLLING FLOW THROUGH THE PORT AND CLOSED BY GAS PRESSURE WITHIN THE PASSAGE, A PLUG DETACHABLY SECURED TO THE BODY, A BORE WITHIN THE PLUG THAT IS IN COMMUNICATION WITH THE PASSAGE TO PROVIDE A CONSTANTLY OPEN PRESSURE-RELIEF ORIFICE, AND SEVERAL CROSS-BORES BETWEEN THE BORE AND THE ATMOSPHERE. 